The present invention relates in general to measurement of oxygenation-related parameters of a patient during surgery, and, more specifically, to a near infrared spectroscopy sensor device having reusable and disposable portions and specially adapted for monitoring hemoglobin level and/or oxygen carrying capacity of blood in the brain during cardiac surgery.
During cardiac surgery, it is very useful for surgeons to monitor oxygenation-related parameters within the brain. Major causes of neurological damage during cardiac surgery include decreased cerebral blood flow, insufficient oxygenation, insufficient hemoglobin concentration, and cerebral embolism. When the brain experiences low oxygen levels during surgery, there is increased risk of neurological problems after surgery which often results in a greater need for critical care and longer hospital stays. Use of brain monitoring devices can help members of the surgical team monitor changes in the oxygen level and/or hemoglobin concentration of the brain and take action before brain damage occurs.
Some previous methods of monitoring the brain were invasive and created other medical risks. Near infrared spectroscopy (NIRS) has been developed as a noninvasive method of monitoring the oxygen level and hemoglobin concentration of blood perfusing the brain employing light emitters and sensors attached to a patient's forehead. Known systems have had unresolved problems in that current sensors are large and bulky and can be affected by exterior light sources. The sensors also have difficulty staying attached to the forehead. Smaller sensors are needed that not only stay firmly attached to the forehead, but leave room on the forehead for other monitors, such as a BIS monitor for anesthesia monitoring. Thus, there is a need in the art for a small NIRS sensor device that stays firmly attached to the patient's forehead and is less affected by outside light.
There exist further unmet needs to ensure safe, hygienic use of NIRS sensors from the standpoint of the patient and to improve efficiency, ease of use, and ease of integration with other surgical/monitoring systems from the standpoint of the medical practitioner.